1. Field of the Invention
The present invention concerns a rotor blade hub for a wind power installation.
2. Description of the Related Art
Such a hub represents a mechanical connection between the (horizontal) rotor shaft (rotor spindle) and the rotor blades. This means that all forces which occur at the rotor blades, insofar as they are not forces in the rotor blades themselves, also occur at the hub. Besides the (intentional) rotational forces, these involve inter alia also centrifugal forces and forces, loads and moments which arise out of the action of the wind on the rotor blades.
The rotor hub is accordingly one of the most highly loaded parts of a wind power installation and, as the connection between the rotor blades and the ‘rest of the installation’, it constitutes the component whose strength must guarantee that no rotor blade can tear away from the installation.
Therefore in the state of the art in most cases rotor blade hubs are produced as a whole from a casting, preferably a component consisting of cast iron with spheroidal graphite.